The objectives are: 1. to improve our isolation technique in order to obtain pure preparations of mucosal cells; 2. to determine the cellular and subcellular distribution of the olfactory receptors; 3. to identify the protein aggregate and polypeptides constituting the olfactory receptor sites. Separation of the mucosal cells will be done by improving our previous technique. An attempt will also be made to separate the cells by changing their physical properties. Preliminary results have shown a correlation between amino acid binding effectiveness to isolated olfactory cells and the electrophysiological activity of these amino acids. This will be used as the main criterion to assess the presence of a receptor in mucosal fractions. The cellular distribution of olfactory receptors will be determined on isolated and deciliated olfactory cells and on isolated cilia. The subcellular distribution of receptor sites will also be followed on cell subfractions. The identification of the protein aggregate constituting the receptor site will be performed by gel filtration. The polypeptides constituting the receptor site will be identified by two techniques: 1. a radioactive amino acid will be covalently linked to the receptor site by photoaffinity labeling, and the protein subsequently separated by two dimensional gel electrophoresis; 2. conversely, the olfactory proteins will be separated by non denaturating electrophoresis, eluted from the gel and tested for the presence of an olfactory receptor.